Texas Compressed Natural Gas (CNG) Delivery Truck Driver Practice Exam

The compatibility of piping and fittings in CNG systems with the fuel under service conditions is essential to ensure safety and functionality. CNG is delivered under high pressure and can impact the integrity of the materials used if they are not specifically designed to withstand these conditions. The interaction between the fuel and the materials must be evaluated to prevent leaks, fractures, or other failures that could lead to hazardous situations. Using materials that can handle the chemical and physical properties of the fuel, including any potential swelling, embrittlement, or degradation, is crucial in maintaining a reliable and safe CNG system. While high-temperature conditions, specific weights of the fuel, and environmental stress factors may also have an impact on material selection, the primary focus must be on the direct compatibility of the materials with the CNG, as it is the most critical aspect in maintaining the system integrity and operational safety.